A headwind is when a fast-moving wind blows against the direction a plane is flying in. Conversely, a tailwind is when air blows in the direction of a plane.
Predictably, headwinds hinder planes during cruising by increasing the drag acting on them, while tailwinds increase a plane’s speed during cruising by reducing drag.
That being said, headwinds are beneficial when a plane is taking off or landing; and tailwinds hinder planes during takeoff and landing.
As a result, both headwinds and tailwinds have their uses.
Although headwinds and tailwinds are usually at a stable speed, wind shear, which is a rapid change in the wind’s direction or speed, can drastically disrupt them.
A headwind is beneficial during takeoffs and landings, since airfoil moving into headwinds generates more lift than air moving through calm wind or even with a tailwind of equal speed.
In fact, pilots and air traffic controllers prefer taking off and landing planes in the direction of a runway that provides a headwind.
Aircraft carriers also take advantage of headwinds by turning towards them when planes need to take off or land.
When is a Tailwind Beneficial?
A tailwind is beneficial when a plane is cruising, as tailwinds reduce the amount of fuel used and increase the plane’s speed, so a plane will reach its destination faster and more economically.
When is a Headwind or Tailwind Detrimental?
A headwind is detrimental to a plane when cruising, as the headwind increases drag, which then increases the flight time.
A tailwind is detrimental during takeoffs and landings.
The tailwind decreases the plane’s climb gradient, which is the ratio between distance travelled over the ground and altitude gained.
The result is that planes reach their desired altitude during landings and expected level during landings later than expected.
Additionally, planes need more runway to compensate for tailwinds during a takeoff. So pilots prefer taking off when there isn’t a tailwind.
How Headwinds and Tailwinds Are Calculated
Headwinds and tailwinds are calculated with the following equation:
Headwind/tailwind speed =wind speed * cos(α )
α is the wind’s angle from the plane’s direction
α is calculated by subtracting the heading of the plane from the heading of the wind.
Example
Suppose for calculating the headwind, the wind speed is 10 kt at an angle of 140 degrees, and the plane has a heading of 110 degrees. α will be 140-110=30.
Plug the values in the formula: headwind = 110*cos30.
The answer is 8.66.
What is a Crosswind?
A crosswind is when wind blows from the side of an aircraft.
Crosswinds can affect light operations, fuel burn, and passenger comfort.
The Relationship Between Jet Streams, Headwinds and Tailwinds
Headwind and tailwind refer to the wind direction a plane experiences during flight.
Headwinds and tailwinds vary depending on time, location, and the plane’s direction.
In contrast, jet streams are naturally occurring strong winds that flow west to east over the earth, and aren’t defined by their relation to the plane.
The jet streams can provide a plane with a tailwind or headwind, depending on the plane’s direction. The jet streams exist regardless of the plane’s direction.
What is the Relationship Between Wind Shear, Headwinds and Tailwinds?
Wind shear is a change of wind speed or direction over short distances, either horizontally or vertically.
Wind shears are normally caused by temperature changes or density gradients, and occur at both low and high altitudes.
Wind shears can drastically change the headwind or tailwind a plane experiences.
The change in tailwinds and headwinds could increase or decrease a plane’s lift.
Pilots normally take corrective actions wherever they encounter wind shears.
In conclusion:
Headwinds and tailwinds describe fast-moving winds that travel against and in the direction of the plane, respectively.
Headwinds hinder planes during flight through increased drag, while tailwinds assist planes by reducing drag.
Headwinds are more beneficial for planes during takeoffs and landings.
Conversely, tailwinds are undesirable for planes during takeoffs and landings.
Headwinds and tailwinds are defined by their relation to the plane’s direction.
In contrast, the jet streams are a series of fast-moving winds over the earth’s surface, and aren’t defined by their relation to a plane’s direction of travel.
Helen Krasner holds a PPL(A), with 15 years experience flying fixed-wing aircraft; a PPL(H), with 13 years experience flying helicopters; and a CPL(H), Helicopter Instructor Rating, with 12 years working as a helicopter instructor.
Helen is an accomplished aviation writer with 12 years of experience, having authored several books and published numerous articles while also serving as the Editor of the BWPA (British Women Pilots Association) newsletter, with her excellent work having been recognized with her nomination of the “Aviation Journalist of the Year” award.
Helen has won the “Dawn to Dusk” International Flying Competition, along with the best all-female competitors, three times with her copilot.
